I know that Fleetwood Mac: Rumors and Toy Matinee have high frequencies in the subwoofer channel. I'm pretty sure that other DVD-As I have are similar but I obtained them after I got the 950.
The Barenboim collection of Beethoven Symphonies is 5.0.

If you want to chase this, plug the subwoofer output of your DVD player directly into your subwoofer. For the full effect, your sub needs a switch to disengage any crossover in the sub itself and a volume control. If you have the crossover switch, just turn it on and off and you'll hear that there's more material than a subwoofer should be asked to handle. I took it a step further and plugged my DVD player's output into an amp driving a full range bass guitar cabinet. On Rumors (Don't Stop, I think), you can clearly hear early reflections of the vocals and snare drum. On Toy Matinee's first "cut" (Can we use that term anymore? ), you'll hear the bass guitar in full range.

Now, the 950's BM for the 6-channel direct works perfectly for me. The loss of the high frequency stuff in the sub channel is hardly noticeable and the other 5 speakers aren't trying to play bass. Still, the mixing engineers need to come up with a standard or, at least, a labeling system, as Bossbass suggests, so the user knows what he or she is dealing with.